Please help me with this question

Dear student,
Please find below the answer:

1. Pacemaker- SA node
2. Stroma- Site of light reaction
3. Afferent nerve- Transmit impulses from receptor organ to spinal cord
4. Prolactin- Stimulates production of milk by the mammary gland
5. Saccules- Associated with static body balance

Hope this clears your doubt.
Regards.